Vulcanizing mold



Aug. 10 1926.

annum? Aug. 10 1926. 1,595,193

4 E. HOPKINSON VULCANIZING MOLD Orginl Fil-'Bd April 18. 1922 2 Sheets-Sheet 2 attenant Patented Aug. 10, i926..

UNITED STATES 'VULGANIZING MCilL i originel. appicatonled April i8, 1922, solltet Nm 5$5,t94. Divided sind this emite-attori filmt ltotemlwr i i l H, 19563. ticrlal No. S3,6t'.

This invention relcteo to .the meiiufac tore of tires and more perticuerly to .uccidoy for their viilcaliizotioii in c serviceable condition and sha/pci,

t -lire vulcchizihg 'molde have heretofore `loeeii mede hy casting or torging them iii iron or steel roughly to chope cod schsequently iriechining there, particularly their cavity faces, to the erect contour de-l m tired.. The machining operations are quito expensive, laborious, end ti.mecoiieumi11g, `jporticiilorly eo in ieshioriini' the tread do sign, Which in moet casco ie one by tedious end` diliicult engrevioff.

tti i The present invention cime to provide o mold that ie somewhat superior to :lily that lim heen used heretofore in ,that it corea the tires better and externally smoother: v A further-ohject ot the invention ie to protl "vide a, mold with si form ot lining that may be removed and remede Without orly addi-- tional materiel, or c very negligible addi tion, to either duplicate the originel and slightly worn-out shapeg or to impart e new 2t contour to the cavity facce et the mold@ thus f reducing the cost of replacements or chauffes 4iii shape Still'another obect of the m-` mention is to provide o mo d that con he inode cheaply and rapidly, and therefore Il@ will not "veriy and unduly delay Iconotec-- tuners in. changing the forro oit their produ niet, or in. meeting an eiriergency suchl its im urgent requirement for production iii? excess lot the capacity of the mold equipment ori 3ft hand.,

" if This application is a division of my co'- peiidirig application, Serial Nor .liilh tiled April lh i922. lWithout intention to limit more than ie l required by the prior crt, the invention may he seid to ooiisist in c mold having c, lining foii its inner or tire contacting tace which h3 cost iii cito and preferably in :i liniehed x or substantially finished condition to the 45 erect contour desired. The mold is mede toy cceti11g,'torging, or machining, each ot itc sections out et cast iron, or steel, or other Weerresistant motel iii the form of e. ring which lie-.e one of its sides groored or '50 liollowed out to approximate theoutlioe oit ctirc that is to be mede, t-hehollow' or M-froore boing mede larger however thori-` the ,1 .re to provide for the reception of e, lining. j inotrii, or form, ie then referer-lily matie t@ out ot Stecher other cuitelhle roeteriel7 iii replica preferably of halt ot .e tire eodwitli the portions which fire duplicate ot the treed desieiil--miorojectioiie or roceeseo--defioed pcrttly yot least hy eeporote mid removable section@ or eegiochte. Alcool', the eoeerohled iriatrix, which ie leid ori e pouriiigtcliley the enculer ring or shell io poeitiohed trod secured to thct molten motel moy he poured or forced :hito o ccyitf, thrit doiiiied hetweeir the Shell ood metric, cod git/'eh the exact cooiigoretioii it io dccired toi-oh tain, on the tire engaging tore or Woll ot each Section of the mold. 'llieii the toctrir: ie removed cod e eimilor procedure fol-- loWed in, melting( the other heilt` ot 'the tire Volcoriiziiig incid. f 4

A, preferred eihhodiiiieht oi the invention is illustroted iii the ziccoropciiyihg drawings in 'which t?,

Figure Il ic o, croco-section ot' mold heli einig lined 'with cost motel heilig cet or soliditied ogg-chiot c metric or torio oi ooit chie conligoretioii; V

Figure E); ie o, section through the mold halt on. the line Qmyliiggure Figure 3 shows completed mold ende tire casing Within. the come mi it opteert 'when vulcanized;

Figure 4f is o perspective ot e. typical forro oi' -ren'iovalile tree d segment, end

Figure t ie o cross-Section nt the treed forming region ot o, mold, showing e slightly modified construction 'of the outer shell et the parting between the mold sections.

lo Figure 3 oi the cli-[twingo e, complete wilccnizingg mold l is chorro io. crooeiiectioh io cooperative relation with e eeelirigwriiig it, between which letter luid the ohoolcrooc 'tiene 3 und 4l ot the mold, the. hooded porIn tiene l5 of o tire casing 6 ere clit-tripod While a Huid under o pres-sere oi from lo() to 200 periode, more or lees, if; applied to the im eide of the ciierigr Each of the sections 3 and l ot the mold consists of an outer shell or Woll tot iron,v steel, or other suitable rigid Wezi-i1-iesiste1it metal, d on inner well or lining 8 oit :my suitable .ietcl that .may he cast iii c iiiiehed condition iii its 3oeitiori in. the mold. White metal containing; tiri cod lood moy he ehiu ployed for the lining het l prefer to use on aluminum Lilloy' 'with chout .113% copper, which has o herd ctrmztiirey congecls ood eolidiiice with c smooth @ottico thet tiriiches the tire het-ter than the old iii:rtericio9 ood deco not tencciouely cling' to il I w e'jriliccoiced or cured eating. Etch eheh it: holtmmrt out PATENT critico,

ERNEST HIKINHQN, 0F YORK, N,

Mill

or grooved on one of its sides, as indicated at 9, a little larger than the tire to be cured in the mold and preferably notched or channeled, as indicated at 10 and 11, to provide for anchorage of the lining against displacement. Ports or holes 12 are provided through the Walls ofthe annular shell T for the passage of molten metal, preferably at spaced intervals, and either through its sides, as shown, or through its outer periphery, as convenient.- The lining is cast to the exact shape of the cavity desired and contacts substantially Vvvvith the entire exterior of the tire casing. Preferably, however, the lining terminates immediately above the portions of the mold which in use engage thebeaded margins of the casing, these portions of the mold being defined, in the case illustrated,` by ribs 13 in eachof the tivo sections, extending inwardly from and in tcgral with the hard Wear-resistant outer ivall or shell 7. The ribs 13 are not essential however, but are desirable to protect the edges of the lining and prolong its serviccability.' Ribs 14, see Fig. 5, may be provided y to similar advantage at the tread center of the mold, against Wear there Where the usage is most severe and Where the faces of the sections contact and are subjected to pressure in service, these last-named ribs in addition servingto secure the lining against displacement and rendering unnecessary, or vless necessary, the provision of notches or channels 10 and 11 in the outer shell.

yThe mold shown in Fig. 3 and above described in detail, or various modifications of lits type, may be manufactured with great ease and dispatch in a manner now to be described.

' I first make the outer shell 7 in any suitable manner,vas by casting, or forging, or stamping, With or Without a rough machining operation in a lathe or mill. The groovev 9 is desirably roughed out or blasted clean, but those of its faces which are to engage with the tire casing during a cure, such as .the ribs 13 and 14;, are accurately machine finished.

l: also make a matrix, or form, indicated generally at 15,-preferably of steel and hardened to preserve its sharp outlines- Whose surface 16 is preferably a replica of half of the tire for which it is intended. The matrix may be in one piece, if the cavity is smooth and concave from tread to bead, or so shaped that it can be Withdrawn Without injuring the lining metal. But if the mold is to be provided with indentations or projections to form a superficial design in the tire, preferably form the matrix with removable sections` 17 and 18, carrying the projection portions of the design and having suitable draft, as at '19, between their interengaging faces where necessary. The drawinf` shows a mold forvulcanizing the tread of a Well-known casing (i, Fig. 3, Whose tread design consists of a central and continuous rib 21, which is flanked on opposite sides by broken ribs Q2 constituted by spaced blocks. For the production of this particular type of tread design in thc mold, and :is an example, I preferably malte the section lT of the matrix a continuous annular ring und the segments or sections 18 arcuate in forni and carrying a suitable number of projcc tions Q3, which are cach a replica of tbc rubber blocks 22 in thc casing that is to bc cured in the mold. The number of projections 23 on a segment may bc varied to nicct requirements, it being essential only to provide sufficient draft or clearance on all sides so as not to mar the lining 8 1n removing the parts of the matrix carrying the tread design. A

About the matrix 15, the outer shell T is positioned, as shown in Fig. 1, and held or secured to a pouring-table 24 in any suitable manner. The matrix is preferably formed with an annular shoulder Q5 corresponding in shape and size to the margins of the scaling-ring 2, or core, if the tireI casingr is to be curcd on a core. And the outer slicll 'i' is machined, or otherwise formed, to interdit with the shoulder 25 of the matrix so as lo close one edge of thc cavitybetwccn thc matrix and the groove 9 in thc shell. the other edge of the cavity being closed cithcr by the support or table 24, as shclwn in Fir l, or by a rib 1S of the out-cr shell. if the latter'has been formed thereon. With thc outer shell and matrix assembled to define a cavity, as described, molten metal is cithcr poured or forced under several hundred pounds pressure through the holes lil in the sides or outer periphery of the shell.

lVhen the metal congeals or solidiiics. the matrix is removed. -If of the construction illustrated in Fig. l, the annular section 1T of the matrix is iirst Withdrawn by n lateral movement thereof. then the segments 18 carrying several of the tread projections Bil are shaken or picked out, these being movable ii yvardiy and preferably radially of the mo d section until clear of the soft lining, an'fad then laterally. When all of the segments have been removed, the body portion of the' matrix is then taken out by lat eral movement. The slugs 2G of cast metal are finally trimmed off even with the surface of the shell. The other and complementary section of the mold is made iii a corresponding manner.

have illustrated and described a type of mold that is especially adapted for curing tires under internal fluid pressure. Butit is to be understood that the saine general construction may be ein loyed for molds used to cure tires While tiey are supported on rigid or collapsible cores or to cure solid tires. lt is obvious, of course, that thc niai trix may be variouslr sections earr in ciples of ther present invention 1n one side thereof, assembling a matrix.

villing s'ectioiied or parted to obtain any desire tread con-figuration.

l Provision may be made for first removing y the larger part'of the matrix'from the mol section, when its lining has been cast in place, by suitably locating the lines of parting or cleavage between it and the` set of the projections of the t tread case a plurality of sets of read segments may be emplo ed and production of the molds increased The rinn are not, t erefore, limited "to all of the precise details of construction and procedure outlined in the foregoing. specification and reference should be made to the appended claims for an understandin of its scope.

Having t us described my invention, what I claim and desire Patent is design, in w ic 1. A method of making a tire vulcanizingmold section which consists in, making an annular rlng with a notched annular groove which is a re lica of atire divided by a plane passed t rough the center of its tread, t e matrix consisting of sections which carry outwardly extending projections when assembled, placing the ring about the matrix, the groove between the ring and the matrix with a metal capable o1' solidifying in a finished condition, -and subsequently removing the matrix without marring the metal linin 2. A met od of making a tire vulcanizing mold which consists in., fashioning an annular ring with a notched annular groove in one of lts outer sides which` is larger than but follows the outline of half of a tire whose, tread is irregular, making a matrix,

' g a replica of the tire half and in sections some of'which at least may be moved raf .dially of the matrix and which carry one or more outwardly extending projections, as-

to protect by Letters th matrixkforcing molten metal into the cast- 'l ing cavity at a plurality of points about its circumference, and after the metal has congealed removing the matrix without substantially marring the outline imparted by it to the cast metal.

3. A method of making a tire vulcanizing mold which consists in, fashioning an annular ring with a notched annular groove in oneof its sides which is larger than but follows the outline of half of a tire, making a matrixa' replica of the tire half andin sections some of which at inwardly of the matrix and which carry outwardly extending projections, assembling e ring and matrix upon a pourngtable and fixing them thereto so as to define -a casting cavity between the ring and matrix, forcing molten metal under pressure into the casting cavity, and after the metal has congealed removing stantially ,'marring it to the cast metal.

4. A method of making a tire vulcanizing mold section which comprisesassembling a sectional core so that some of the sections will carry outwardly extending rojections, the assembledV core having the surface conformation, placing the core in a mold having a notched annular inner sur# face and arranging the core and moldso that the tire surface of the-core is spaced` apart from the surface'of the mold, then pouring molten metal into the space between the mold and core and removing the indi vidual sections of the core. t

Signed at New York city, county of New York, and State of New York, this 2nd day of November, 1923.

the outline imparted by least may be moved esired tire the matrix without sub--A 

